COPAXONE® is the trade name of glatiramer acetate, an FDA approved drug for the treatment of multiple sclerosis. COPAXONE® is also known as Copolymer-1. The COPAXONE® label discloses that COPAXONE® consists of the acetate salts of synthetic polypeptides, containing four naturally-occurring amino acids: L-glutamic acid, L-alanine, L-tyrosine and L-lysine with an average molar fraction of 0.141, 0.427, 0.095 and 0.338, respectively, and has a weight average molecular weight of 4.7-11.0 kilodaltons (kDa). COPAXONE® comprises a mixture of polypeptides having different molecular weights and sequences. The structural formula of COPAXONE® is:(Glu,Ala,Lys,Tyr)x.xCH3COOH(C5H9NO4.C3H7NO2.C6H14N2O2.C9H11NO3)x.xC2H4O2 
COPAXONE® is a white to off-white, sterile, lyophilized powder containing 20 mg glatiramer acetate and 40 mg of mannitol. It is supplied in single use vials for subcutaneous administration after reconstitution with sterile water.
Processes for preparing Copolymer-1 or glatiramer acetate have been described in U.S. Pat. Nos. 3,849,550; 5,800,808; 5,981,589; 6,048,898; 6,054,430; 6,342,476; and 6,362,161. The process for the synthesis of glatiramer acetate is based on the polymerization of N-carboxyanhydrides of tyrosine, alanine, γ-benzyl glutamate and Nε-trifluoroacetyl lysine in anhydrous dioxane at room temperature using diethylamine as initiator, to form a protected polypeptide. The deblocking of the γ-benzyl groups (first deprotection) is accomplished by stirring the protected polypeptide in hydrogen bromide/acetic acid at room temperature. These conditions also facilitate the cleavage of the copolymer. The next step is the removal of the Nε-trifluoroacetyl groups (second deprotection) of the copolymer by treatment with 1 M piperidine. In the final steps, glatiramer acetate is obtained by purification of the copolymer through dialysis, followed by treatment with acetic acid to form the acetate salt and by another purification by dialysis against water. Thus, these prior art processes involve the polymerization of four N-carboxyanhydrides, two deprotection steps, two purification steps and one acetate salt formation step.
U.S. Pat. No. 6,620,847 describes a process for preparing Copolymer-1 which involves treating trifluoroacetyl Copolymer-1 with aqueous piperidine to form a solution of Copolymer-1 and purifying Copolymer-1.
U.S. Patent Application Publication No. 2004/0091956 describes a three-step process for preparing glatiramer acetate. The process involves polymerization of a mixture of the N-carboxyanhydrides of L-alanine, L-tyrosine, protected L-glutamate and protected L-lysine, to obtain a protected polypeptide or salt thereof; and deprotection of the protected polypeptide or salt thereof by either palladium catalytic transfer hydrogenation or palladium catalytic hydrogenation under hydrogen pressure.